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Biomedical subjects

B Fontaine

Publications and source records attributed to B Fontaine.

175 records · Page 10Linked to original sources
PubMed1982

[Clinical study of prostacyclin in extracorporeal circulation. Effects on hemodynamics and coagulation].

The effects of prostacycline (PGI2), the most powerful known platelet antiaggregant on platelet count and function during cardiopulmonary bypass, were assessed in a double blind study. One group of 13 patients received 2,5 mg/Kg of Heparin with an infusion of 25 ng/Kg/min of prostacycline instituted 15 minutes before the Heparin, continued at the beginning of cardiopulmonary bypass at a dose of 50 ng/Kg/min and terminated at the end of bypass. A second group of 15 patients were studied by the same protocol with a placebo infusion. The platelet count was significantly higher at the end of cardiopulmonary bypass in the Prostacycline group. Platelet aggregation was reduced by comparison with the control group from the beginning of Prostacycline infusion. The active thrombin time was significantly longer in the Prostacycline group. However, blood loss did not differ significantly between the two groups although it was less in the study group. The platelet count and function during cardiopulmonary bypass with Prostacycline was therefore increased and resulted in a reduction in Heparin consumption.

Anticoagulants↗
PubMed1981

[Emergency in neo-natal surgery. High risks in forty-one cases (author's transl)].

41 babies were operated upon in emergency in the cardiac surgery department. 11 of them were submitted to open heart surgery and 30 were operated without extra corporeal circulation. Amongst them, there were 21 coarctations of thoracic aorta either isolated or associated with other cardiac malformations. 13 of them, presented a pericardial effusion, and the mean age was 3 months. First of all, the notion of emergency in cardiac surgery of the new-born is stressed. Then, premedication and technic of anaesthesia are shortly described. The authors insist on the frequency of lethal cardiac fibrillation occurring at the opening of pericardium in case of coarctations of aorta complicated by pericardial effusion. Prevention of this accident is possible if at the beginning of anaesthesia the baby lies in a proclive position. On the opposite, bradycardia occurring at the opening of the pericardium or during pulmonary artery banding have a good prognosis. Lastly, the authors insist on the high risk of this surgery in the baby (25 p. cent of mortality) and 80 p. cent under 6 months of age and the high mortality of iterative operations.

Anesthesia↗
PubMed1980

[Investigation of obliterative arterial disease of the lower limbs, by muscular scintigraphy using thallium (author's transl)].

The behaviour of thallium is similar to that of potassium. It participates in transmembrane exchanges and accumulates within the cells, in particular muscle cells. The subjects being at rest or at the maximum phase of an effort test, an injection of 2 mCi of thallium 201 as given. Quantitative scintigraphies were performed during the minutes following injection. Ten control subjects were studied in this way. Uptake of thallium in the muscle masses of the lower limbs was symmetrical and homogeneous and was more marked after effort. Acute ischemia for a few minutes was obtained using a tourniquet in a volunteer. The ischemic area was clearly seen on the early scintigraphy. There was redistribution of thallium in the later scintigraphic studies. Fifteen patients with obliterative arterial disease underwent scintigraphy at rest and after effort. Good agreement was found between arteriography, measurement of pressures, plethysmography and deficiencies demonstrated by scintigraphy. The effort test, by inducing transient ischemia, was useful in detecting moderate circulatory disturbances.

Adult↗
PubMed1979

[Prinzmetal's angina during myocardial revascularisation. Cardiovascular complications in 71 patients (author's transl)].

71 patients undergo myocardial revascularisation for Prinzmetal's angina; among them, 50 p. cent are operated upon in emergency according to three ways of anaesthesia: neuroleptanalgesia, analgesic anaesthesia, combined anaesthesia. The authors lay stress on the importance of per- and post-operative complications: electrocardiographic ischemia in 22 p. cent of the cases, severe ventricular excitability perturbations were observed in 21 p. cent, myocardial necrosis in 14 p. cent, cardiovascular collapse in 21 p. cent and hypertensions in 22 p cent. These complications are often associated. In the discussion, the authors underline anesthetic induction as a cause of Prinzmetal's angina in 50 p. cent of the cases. They put the accent on the severity of peroperative crisis followed in 50 p. cent of the cases by serious ventricular excitability perturbations. In 25 p. cent of the cases myocardial necrosis is a complication of the spasm of a coronary artery. In this field, posterior necrosis are more frequent and correspond to the spasm of the right coronary artery. All the patients of this series, except one, develop necrosis in the spastic area (by-passed or not). Per-operative hypertension has no incidence on the occurrence of post-operative complications. Lastly, continuous per-operative infusions of nitroglycerine has been performed in several patients in order to reduce morbidity of this type of surgery.

Anesthesia↗
PubMed1979

[Anesthesia for aorto-coronary bypass].

The authors have analysed a series of 357 patients undergoing aortocoronary bypass. The onset of complications was studied in relation to the past history, the anaesthetic protocol, the period of extra-corporeal circulation and the type of myocardial protection. Complications consisted of acute hypertensive episodes, arrhythmias, peroperative myocardial ischemia and myocardial infarction. The degree of beta-blocker therapy and above all its continuation up to the time of operation would seem to be an important factor in effective myocardial protection.

Anesthesia↗
PubMed1978

[Disinsertion of the left innominate vein during median vertical sternotomy (author's transl)].

The left innominate vein may be torn during median vertical sternotomy. This tear may in fact be a disinsertion of the venous trunk from the superior vena cava. Repair of this disinsertion is difficult, with a risk of stenosis. It requires the most careful technique, after dissection of the superior vena cava on either side of the tear. It is made much more simple by the use of extracorporeal circulation, which empties and collapses the superior vena cava. Finally, it may be necessary to repair this loss of substance by enlarging it with a fragment of saphenous vein.

Brachiocephalic Veins↗
PubMedDate not supplied

The human CDC42 gene: genomic organization, evidence for the existence of a putative pseudogene and exclusion as a SJS1 candidate gene.

Schwartz-Jampel syndrome (SJS) is an autosomal recessive human disorder characterized by myotonia and osteoarticular deformities. Three types are distinguished based on age at onset: types 1A, 1B and 2. We have previously localized the SJS1 gene, responsible for types 1A and 1B, on human chromosome 1p35-p36.1 in a region frequently rearranged in human tumours. The CDC42 gene, for which divergent localizations have previously been described (chromosomes 4, 7 and 20), has been mapped within the SJS1 critical interval by radiation hybrid and yeast/P1 artificial-chromosome-based physical map analyses. The CDC42 gene product is a small GTPase protein of the Rho family mediating a variety of signaling pathways including cytoskeletal rearrangements, cell-cycle progression and transformation. To search for mutations in SJS1 patients, we have determined the organization of the human CDC42 gene on chromosome 1p and found that it encodes for the placental and brain isoforms generated by alternative splicing. No mutations have been found in SJS1 patients, excluding CDC42 as the SJS1 gene. Interestingly, we have demonstrated that a CDC42-like transcript gene located on chromosome 4 does not contain introns and is similar to the placental isoform, suggesting that it is a processed pseudogene. The determination of the CDC42 gene structure described in this report should facilitate future studies of the potential role of CDC42 in human disorders.

Amino Acid Sequence↗
PubMedDate not supplied

Calcium use increases risk of calciphylaxis: a case-control study.

OBJECTIVE: To investigate the risk factors for the development of calciphylaxis in renal failure, a poorly understood and often fatal condition characterized by calcium deposition in tissues. DESIGN: Retrospective case-control study. SETTING: University hospital peritoneal dialysis center. PATIENTS: Eight continuous ambulatory peritoneal dialysis (CAPD) patients with calciphylaxis were identified in a 3-year period. We matched up to five controls for dialysis modality and length of time on dialysis with each case. STATISTICS: Multivariate conditional logistic regression analysis for matched case-controls. MAIN OUTCOME MEASURES: Laboratory data and demographics were collected as well as cumulative calcium and vitamin D ingestion over the year prior to disease onset. RESULTS: All the patients were female, versus only 38% (14/37) of controls (p < 0.0001). While not statistically significant, a majority of the patients were diabetic [62.5% (5/8) vs 32% (12/37)]. Peak and average levels of serum calcium, phosphate, calcium x phosphate product, parathyroid hormone (PTH), albumin, iron, total iron-binding capacity (TIBC), and ferritin were not significantly different in cases compared with controls. The use of calcitriol alone or with calcium carbonate was not found to be a significant risk factor for the development of calciphylaxis. In a multivariate analysis, iron intake seemed to be protective, contrary to previous reports, while the use of calcium carbonate was associated with a strong trend to increased risk of calciphylaxis development (odds ratio = 1.029/g and 1.011/g calcium ingested per month, at 1 and 2 - 3 months prior to calciphylaxis development; p = 0.0556 and 0.0565, respectively). CONCLUSION: These data, although limited by the small numbers of index cases, suggest that calcium ingestion is a risk factor for calciphylaxis. The increased use of calcium salts as a phosphate binder in recent years might explain the apparent increased incidence of calciphylaxis in our and other centers. The preponderance of female diabetics among cases reported elsewhere was confirmed in our study.

Calciphylaxis↗